Re: [linuxsh-dev] Small fix for PCI DMA code.

[David W. <dw...@in...>]

Dav...@st... said:
>  I agree. Calling flush_cache_all() was simply done for expediency, I
> just never had the time to do it properly. I think it should be faster
> doing it this way, as you don't need to flush the icache.

OK, committed. Next I need to clean up some broken drivers...

Index: ChangeLog
===================================================================
RCS file: /cvsroot/linuxsh/kernel/ChangeLog,v
retrieving revision 1.328
diff -u -r1.328 ChangeLog
--- ChangeLog	2001/08/14 14:44:58	1.328
+++ ChangeLog	2001/08/14 14:48:09
@@ -1,5 +1,8 @@
 2001-08-14  David Woodhouse  <dw...@in...>
 
+	* drivers/net/via-rhine.c: Make some attempt to actually
+	deal with cache coherency issues rather than just inserting
+	a couple of wmb() calls.
 	* arch/sh/kernel/pci-dma.c: Use dma_cache_wback_inv() in 
 	pci_alloc_consistent instead of flush_cache_all(), which is
 	a nop on SH3. If the size is so large that it's quicker just 
Index: drivers/net/via-rhine.c
===================================================================
RCS file: /cvsroot/linuxsh/kernel/drivers/net/via-rhine.c,v
retrieving revision 1.9
diff -u -r1.9 via-rhine.c
--- drivers/net/via-rhine.c	2001/07/18 02:54:27	1.9
+++ drivers/net/via-rhine.c	2001/08/14 14:48:09
@@ -69,6 +69,9 @@
 	- Manfred Spraul: use "singlecopy" for unaligned buffers
 	                  don't allocate bounce buffers for !ReqTxAlign cards
 
+	LK1.1.11:
+	- David Woodhouse: PCI DMA cache coherency fixes.
+
 */
 
 
@@ -151,7 +154,7 @@
 
 /* These identify the driver base version and may not be removed. */
 static char version[] __devinitdata =
-KERN_INFO "via-rhine.c:v1.10-LK1.1.10  07/12/2001  Written by Donald Becker\n"
+KERN_INFO "via-rhine.c:v1.10-LK1.1.11  14/08/2001  Written by Donald Becker\n"
 KERN_INFO "  http://www.scyld.com/network/via-rhine.html\n";
 
 static char shortname[] __devinitdata = "via-rhine";
@@ -758,8 +761,9 @@
 			    TX_RING_SIZE * sizeof(struct tx_desc),
 			    np->rx_ring, np->rx_ring_dma);
 
-	pci_free_consistent(np->pdev, PKT_BUF_SZ * TX_RING_SIZE,
-						np->tx_bufs, np->tx_bufs_dma);
+	if(np->tx_bufs)
+		pci_free_consistent(np->pdev, PKT_BUF_SZ * TX_RING_SIZE,
+							np->tx_bufs, np->tx_bufs_dma);
 
 }
 
@@ -801,6 +805,8 @@
 		np->rx_ring[i].addr = cpu_to_le32(np->rx_skbuff_dma[i]);
 		np->rx_ring[i].rx_status = cpu_to_le32(DescOwn);
 	}
+	pci_dma_sync_single(np->pdev, np->rx_ring_dma,
+						RX_RING_SIZE * sizeof(struct rx_desc), PCI_DMA_TODEVICE);
 	np->dirty_rx = (unsigned int)(i - RX_RING_SIZE);
 }
 
@@ -821,6 +827,8 @@
 		}
 		np->rx_skbuff[i] = 0;
 	}
+	pci_dma_sync_single(np->pdev, np->rx_ring_dma,
+						RX_RING_SIZE * sizeof(struct rx_desc), PCI_DMA_TODEVICE);
 }
 
 static void alloc_tbufs(struct net_device* dev)
@@ -841,6 +849,9 @@
 	}
 	np->tx_ring[i-1].next_desc = cpu_to_le32(np->tx_ring_dma);
 
+	pci_dma_sync_single(np->pdev, np->tx_ring_dma,
+						TX_RING_SIZE * sizeof(struct tx_desc), PCI_DMA_TODEVICE);
+
 }
 
 static void free_tbufs(struct net_device* dev)
@@ -863,6 +874,8 @@
 		np->tx_skbuff[i] = 0;
 		np->tx_buf[i] = 0;
 	}
+	pci_dma_sync_single(np->pdev, np->tx_ring_dma,
+						TX_RING_SIZE * sizeof(struct tx_desc), PCI_DMA_TODEVICE);
 }
 
 static void init_registers(struct net_device *dev)
@@ -1124,6 +1137,8 @@
 			return 0;
 		}
 		skb_copy_and_csum_dev(skb, np->tx_buf[entry]);
+		pci_dma_sync_single(np->pdev, np->tx_bufs_dma + entry*PKT_BUF_SZ,
+							PKT_BUF_SZ, PCI_DMA_TODEVICE);
 		np->tx_skbuff_dma[entry] = 0;
 		np->tx_ring[entry].addr = cpu_to_le32(np->tx_bufs_dma +
 										  (np->tx_buf[entry] - np->tx_bufs));
@@ -1136,16 +1151,17 @@
 	np->tx_ring[entry].desc_length = 
 		cpu_to_le32(0x00E08000 | (skb->len >= ETH_ZLEN ? skb->len : ETH_ZLEN));
 
+	pci_dma_sync_single(np->pdev, np->tx_ring_dma * entry * sizeof(struct tx_desc), sizeof(struct tx_desc), PCI_DMA_TODEVICE);
+
 	/* lock eth irq */
 	spin_lock_irq (&np->lock);
-	wmb();
+
 	np->tx_ring[entry].tx_status = cpu_to_le32(DescOwn);
-	wmb();
 
+	pci_dma_sync_single(np->pdev, np->tx_ring_dma * entry * sizeof(struct tx_desc), sizeof(struct tx_desc), PCI_DMA_TODEVICE);
+	
 	np->cur_tx++;
 
-	/* Non-x86 Todo: explicitly flush cache lines here. */
-
 	/* Wake the potentially-idle transmit channel. */
 	writew(CmdTxDemand | np->chip_cmd, dev->base_addr + ChipCmd);
 
@@ -1215,6 +1231,9 @@
 	struct netdev_private *np = dev->priv;
 	int txstatus = 0, entry = np->dirty_tx % TX_RING_SIZE;
 
+	pci_dma_sync_single(np->pdev, np->tx_ring_dma, 
+						TX_RING_SIZE * sizeof(struct tx_desc), PCI_DMA_FROMDEVICE);
+
 	spin_lock (&np->lock);
 
 	/* find and cleanup dirty tx descriptors */
@@ -1264,6 +1283,8 @@
 	struct netdev_private *np = dev->priv;
 	int entry = np->cur_rx % RX_RING_SIZE;
 	int boguscnt = np->dirty_rx + RX_RING_SIZE - np->cur_rx;
+	
+	pci_dma_sync_single(np->pdev, np->rx_ring_dma, RX_RING_SIZE * sizeof(struct rx_desc), PCI_DMA_FROMDEVICE);
 
 	if (debug > 4) {
 		printk(KERN_DEBUG " In via_rhine_rx(), entry %d status %8.8x.\n",
@@ -1368,6 +1389,8 @@
 		}
 		np->rx_ring[entry].rx_status = cpu_to_le32(DescOwn);
 	}
+
+	pci_dma_sync_single(np->pdev, np->rx_ring_dma, RX_RING_SIZE * sizeof(struct rx_desc), PCI_DMA_TODEVICE);
 
 	/* Pre-emptively restart Rx engine. */
 	writew(CmdRxDemand | np->chip_cmd, dev->base_addr + ChipCmd);


--
dwmw2